From previous research on perceptual after effects of maintained convergence and from studies of incomplete relaxation of fusional vergence, it was proposed that after a period of maintained accommodation, the ciliary muscles would remain innervated beyond normal tonic levels even under conditions in which accommodation should be relaxed. It was proposed to test for the hypothesized accommodative hysteresis effects with the laser optometer by measuring the amplitude of accommodation, the level of accommodation in a dark field (i.e., the dark focus), and visual acuity before and after a period of maintained fixation at various optical distances. It was also proposed to examine the dependence of the magnitude and the duration of the accommodation aftereffect on the time period of prior fixation and optical distance to the fixation target.